super easy ques

1.BeSO4>MgSO4>CaSO4>SrSO4
agree with tushar.
larger anions SO4^2-,CO3^2- compared to cation means that the cationic radius doesnt influence the lattice energy much but the hydration energy decreases down the group,making them lesser soluble.
on the contrary when the anion is of similar size as that of the cation,the radius of teh cation will affect the lattice energy and the decrease in lattice energy will be much more than the decrease in hydration energy which causes the solubility to increase down the group as for hydroxides.

@tush ,arka..i too got same answers as urs..but ans given were

1) BeSO4< MgSO4< CaSO4 <SrSO4
2)Cr > Mn >Ti>V

surely they are wrong..

anyone for 3 ?

@Eureka ..r u sure abt the third equation?
i think there is some problem that shud be M₃O₄ ..if that's not a redox reaction...or if it's a redox reaction so M is getting reduced then something shud get oxidised also...

Ans 2.. the trend given by Tushar is correct..actually this is given in NCERT..but dont worry such questions wont be asked...as there is no regular trends in d-block....

eureka,they have 2 b wrong.
CaSO4 is an insoluble white ppt whereas MgSO4 is soluble salt!

@arka,rickde....ya ans are surely wrong...just wanted to confirm form the genius guys out here [1]

@govind.. the eqn maybe wrong....but lets work through equivalents only ..and not by moles..that way it would be easier

M + X₂ → MX₂
3MX₂ + X₂ → M₃X₈
M₃X₈ + 4N₂CO₃ → M₃O₄ + 8NX + 4CO₂

for one mole of NX ..1/8 mole of M₃X₈
for 1/8 mole of M₃X₈ we need 3/8 mole of MX₂
for 3/8 mole of MX₂ we need 3/8 mole of M

so for 2mol of NX we need 3/4 mole of N..and tht's 42 gram

kk..thx....i was making mistake in n factor..got it now...